Weather vane



FIG. 1 is a front perspective view of a weather vane showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a top plan view of FIG. 2.

The broken-line showings of FIGS. 1-3 _are environmental only and form no part of the claimed design. 

The ornamental design for a weather vane, as shown and described. 